A leaded semiconductor package typically has a semiconductor die encapsulated in molded plastic. The plastic encapsulation protects the die from physical damage as well as environmental effects, such as heat, light and/or electricity, for example. The leaded semiconductor package is typically mounted on a board, such as a printed circuit board (PCB), by means of metal leads that protrude from the encapsulation. The metal leads further provide electrical connections from the die to external circuitry that is typically located on the board. For instance, the metal leads are usually soldered or are otherwise electrically bonded to several bonding pads on the PCB.
As described below, so called “leadless” or “no lead” semiconductor packages have also been developed. Many of these semiconductor packages are mass produced by using sheets of leadframe arrays. Leadframes provide a design and preliminary framework for the die pad and/or contact pads of a semiconductor package. However, leadframe technology has had difficulties in forming multi row terminals for leadless packages. For instance, half etching is conventionally used to form leadframes, and to form the connecting bars between the parts of the leadframe, and between the leadframes, themselves. This method of manufacture is often referred to as etched leadframe technology. However, etched leadframes can pose problems during manufacture, particularly during the handling and wire bonding processes. These problems relate to the strength and structural integrity of the leadframes, and thus, have adverse effects on useful yield and quality of the manufactured product.
Accordingly, an additional plastic substrate, which is similar to a PCB, is conventionally used to provide additional strength and structure during manufacture, particularly for leadless packages having multiple rows of contact pads. However, the additional substrate undesirably adds cost, time delay, and other manufacturing problems.